Try this:
clc; % Clear the command window.
fprintf('Beginning to run %s.m.\n', mfilename);
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format long g;
format compact;
fontSize = 22;
delta = 35;
allPhi = [0, 45, 85]
L = 384329*1000;
re = 6376*1000;
Me = 5.98e24;
Mm = 7.34e22;
lambda = [0:5:360];
T1 = (re/4)*(Mm/Me)*(re/L)^3;
for k = 1 : length(allPhi)
phi = allPhi(k);
T2 = 3*((sind(phi))^2)*(sind(delta))^2-1;
T3 = 3/2*sind(2*phi)*sind(2*delta)*cosd(lambda);
T4 = 3*(cosd(phi))^2*(cosd(delta))^2*(cosd(lambda)).^2;
eta = T1*(T2+T3+T4);
subplot(2, 2, k);
plot(lambda,eta, 'b-', 'LineWidth', 2);
grid on
xlabel('\lambda(degrees)', 'FontSize', fontSize);
ylabel('\eta(m)', 'FontSize', fontSize);
% title('\eta(m) Vs. \lambda(degrees) when \phi is 0(degrees)', 'FontSize', fontSize);
caption = sprintf('\\eta(m) Vs. \\lambda(degrees) when \\phi is %.1f(degrees)', phi); % Use double backslashes.
title(caption, 'FontSize', fontSize);
end
g = gcf;
g.WindowState = 'maximized'
fprintf('Done running %s.m.\n', mfilename);
